Problem: $\overline{AC}$ is $6$ units long $\overline{BC}$ is $4$ units long $\overline{AB}$ is $2\sqrt{13}$ units long What is $\cos(\angle ABC)$ ? $A$ $C$ $B$ $6$ $4$ $2\sqrt{13}$
Answer: SOH CAH TOA os = djacent over ypotenuse adjacent $= \overline{BC} = 4$ hypotenuse $= \overline{AB} = 2\sqrt{13}$ $\cos(\angle ABC )=\frac{4}{2\sqrt{13}}$ $=\dfrac{2\sqrt{13} }{13}$